Conventional fuel injection valves are disclosed in Japanese Patent Documents. The conventional fuel injection valves disclosed therein actuate a valve member by an electromagnetic force between a fixed core and a movable core that slidably moves in an axially reciprocating motion. The electromagnetic force between the fixed core and the movable core can be increased by increasing a cross-sectional area of those cores (refer to a Japanese Patent Document JP-A-H11-500509, and a Japanese Patent Document JP-A-2002-528672). The increased cross-sectional area of the fixed core and the movable core receives an increased amount of magnetic flux. Therefore, the fixed core 34 and the movable core attract each other by an increased magnetic attractive force.
However, the increased cross-sectional area of the movable core leads to an increased mass. The increased mass of the movable core deteriorates responsiveness of the movable core when a current is supplied to actuate the movable core. As a result, an amount of injected fuel cannot be precisely controlled.